I do think the open layout helps in that paras can easily circulate between multiple different classrooms. The school seems to spend money on these in-class paras rather than spending money on intervention teachers who pull kids with special needs with math/reading (the other end of the spectrum). So the paras can help with whatever it is the teacher needs rather than being on a rigid pull-out schedule.

Honestly I don't know exactly how DS's teacher makes it work or finds any extra time to work with him and grade the numerous individualized papers she has him do (including giving him his own individualized spelling tests!) but it's working out fairly well. Sometimes I ask him "Who helped you with this?" and he names someone that I don't know.